The micro-hemostat of the present invention is particularly useful in anastomosis which is a surgical technique for forming a passage between two normally distinct tubes or vessels of the body.
A common operation in which anastomosis is employed is a coronary artery by-pass operation in which blood is routed about a blocked portion of a coronary artery to restore and insure adequate blood supply to the heart muscle. In the normal by-pass operation, a short segment of a vein taken from another part of the patient's body is used. One end of this vein is connected to the aorta and the other end is connected to the blocked coronary artery below the blockage. The anastomosis connection between the aorta and the artery serves as the by-pass around the blockage.
The standard operative technique for making a coronary artery by-pass comprises first clamping off the aorta to occlude blood flow to all the coronary arteries. The by-pass connection is then made by suturing the veins in place. Many times multiple by-passes are required, and as a result, it may be necessary for the aorta to be clamped off for an extended period of time during which there is no blood supply to the muscle tissue of the heart or the myocardium. The prolonged suspension of blood supply to the heart can result in life threatening infarcts.
Recently a relatively simple technique for the local occlusion of a coronary artery without aortic cross-clamping during anastomosis was described in the literature. Mullen et al, Anals. of Thoracic Surgery, Vol. 23, No. 1 (July, 1977). In the described technique, the flow of blood through the artery is stopped with an occluding device made of silicone rubber and shaped like a T-tube with bulb tips. The occluder is inserted into the artery through an incision and the bulbs occlude the artery bi-directionally during the anastomosis. The occluders are soft and malleable and available in several sizes to fit different sized arteries. The occluder is removed from the artery just prior to placing the final stitches joining the vein and artery.
The occluder and technique described in the Mullen et al article are a significant improvement over the aorta cross-clamping technique previously used. However, there are surgeons who would prefer a technique in which the incision required for insertion and withdrawal of the occluding device would not have to be so large, in which the operating time consumed in selecting the correct size occluder could be reduced and in which the tissue supplied by the artery would not be without circulation while sizing and using the occluder.